1// Copyright 2012 The Kyua Authors.
2// All rights reserved.
3//
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5// modification, are permitted provided that the following conditions are
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7//
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11//   notice, this list of conditions and the following disclaimer in the
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14//   may be used to endorse or promote products derived from this software
15//   without specific prior written permission.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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27// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29#include "utils/units.hpp"
30
31extern "C" {
32#include <stdint.h>
33}
34
35#include <stdexcept>
36
37#include "utils/format/macros.hpp"
38#include "utils/text/exceptions.hpp"
39#include "utils/text/operations.ipp"
40
41namespace units = utils::units;
42
43
44/// Constructs a zero bytes quantity.
45units::bytes::bytes(void) :
46    _count(0)
47{
48}
49
50
51/// Constructs an arbitrary bytes quantity.
52///
53/// \param count_ The amount of bytes in the quantity.
54units::bytes::bytes(const uint64_t count_) :
55    _count(count_)
56{
57}
58
59
60/// Parses a string into a bytes quantity.
61///
62/// \param in_str The user-provided string to be converted.
63///
64/// \return The converted bytes quantity.
65///
66/// \throw std::runtime_error If the input string is empty or invalid.
67units::bytes
68units::bytes::parse(const std::string& in_str)
69{
70    if (in_str.empty())
71        throw std::runtime_error("Bytes quantity cannot be empty");
72
73    uint64_t multiplier;
74    std::string str = in_str;
75    {
76        const char unit = str[str.length() - 1];
77        switch (unit) {
78        case 'T': case 't': multiplier = TB; break;
79        case 'G': case 'g': multiplier = GB; break;
80        case 'M': case 'm': multiplier = MB; break;
81        case 'K': case 'k': multiplier = KB; break;
82        default: multiplier = 1;
83        }
84        if (multiplier != 1)
85            str.erase(str.length() - 1);
86    }
87
88    if (str.empty())
89        throw std::runtime_error("Bytes quantity cannot be empty");
90    if (str[0] == '.' || str[str.length() - 1] == '.') {
91        // The standard parser for float values accepts things like ".3" and
92        // "3.", which means that we would interpret ".3K" and "3.K" as valid
93        // quantities.  I think this is ugly and should not be allowed, so
94        // special-case this condition and just error out.
95        throw std::runtime_error(F("Invalid bytes quantity '%s'") % in_str);
96    }
97
98    double count;
99    try {
100        count = text::to_type< double >(str);
101    } catch (const text::value_error& e) {
102        throw std::runtime_error(F("Invalid bytes quantity '%s'") % in_str);
103    }
104
105    return bytes(uint64_t(count * multiplier));
106}
107
108
109/// Formats a bytes quantity for user consumption.
110///
111/// \return A textual representation of the bytes quantiy.
112std::string
113units::bytes::format(void) const
114{
115    if (_count >= TB) {
116        return F("%.2sT") % (static_cast< float >(_count) / TB);
117    } else if (_count >= GB) {
118        return F("%.2sG") % (static_cast< float >(_count) / GB);
119    } else if (_count >= MB) {
120        return F("%.2sM") % (static_cast< float >(_count) / MB);
121    } else if (_count >= KB) {
122        return F("%.2sK") % (static_cast< float >(_count) / KB);
123    } else {
124        return F("%s") % _count;
125    }
126}
127
128
129/// Implicit conversion to an integral representation.
130units::bytes::operator uint64_t(void) const
131{
132    return _count;
133}
134
135
136/// Extracts a bytes quantity from a stream.
137///
138/// \param input The stream from which to read a single word representing the
139///     bytes quantity.
140/// \param rhs The variable into which to store the parsed value.
141///
142/// \return The input stream.
143///
144/// \post The bad bit of input is set to 1 if the parsing failed.
145std::istream&
146units::operator>>(std::istream& input, bytes& rhs)
147{
148    std::string word;
149    input >> word;
150    if (input.good() || input.eof()) {
151        try {
152            rhs = bytes::parse(word);
153        } catch (const std::runtime_error& e) {
154            input.setstate(std::ios::badbit);
155        }
156    }
157    return input;
158}
159
160
161/// Injects a bytes quantity into a stream.
162///
163/// \param output The stream into which to inject the bytes quantity as a
164///     user-readable string.
165/// \param rhs The bytes quantity to format.
166///
167/// \return The output stream.
168std::ostream&
169units::operator<<(std::ostream& output, const bytes& rhs)
170{
171    return (output << rhs.format());
172}
173